Fluid type, rate do not curb 90-day mortality rate in ICU patients requiring fluid challenges

NEW YORK (Reuters) – For critically ill patients requiring fluid challenges, a balanced solution was no better than normal saline and a slower intravenous bolus rate was no better than a faster rate in a multicenter randomized trial in Brazil.

“The Balanced Solutions in Intensive Care Study (BaSICS) study tested whether a solution that resembles more plasma composition (‘balanced’ or ‘buffered’ solutions with lower chloride content, neutral pH) would be better than 0.9% saline, which is the standard fluid in many scenarios.,” Dr. Fernando Zampieri of the HCor Research Institute in Sao Paulo told Reuters Health by email.

“Previous studies suggested that these buffered solutions could be associated with better mortality and less kidney injury in those patients,” he said.

“Additionally,” he noted, “the rate that is applied for (infusing) fluids lacks proper evidence and varies widely across different settings.”

Dr. Zampieri was the first author of the studies of both aspects of ICU treatment, published in JAMA on Aug. 10 and presented simultaneously in part at the Critical Care Reviews livestream.

BaSICS included 10,520 ICU patients randomized to different fluids and infusion rates. Participants had a mean age of about 61 and about 44% were women. The primary outcome was 90-day survival.

IV treatment with a balanced versus a normal saline solution resulted in 90-day mortality of 26.4% versus 27.2%, respectively, a difference that was not statistically significant.

Dr. Zampieri added, “BaSICS reported that buffered solutions may even be associated with harm in one important subgroup of patients, namely those who suffered traumatic brain injury. These patients should now not be treated with balanced/buffered fluids.”

In the infusion rate analysis, treatment with fluid boluses at 333 mL/h versus 999 mL/h resulted in a 90-day mortality of 26.6% versus 27.0%, a difference that was not statistically significant.

Dr. Zampieri noted, “it should be highlighted that a slower infusion speed was associated with marginal benefits at 3 days of ICU stay, mostly due to a lower need for medications to increase blood pressure at that time. While this is not a patient-centered endpoint such as mortality, duration of ICU or hospital stay, among others, it should prompt future studies to evaluate this frequently neglected aspect of fluid therapy in critically ill patients.”

Further, the study found no significant interaction between fluid type and infusion rate.

Dr. Zampieri said: “By reporting that the standard of care (0.9% saline) is acceptable and not associated with harm, it allows centers to remain using their standard fluid. This is especially relevant for low- and middle-income countries that do not have buffered solutions easily available.”

“The infusion rate study also rendered neutral results,” he said. “This suggests that using faster infusion rates is not associated with meaningful benefits for critically ill patients.”

Dr. Craig Coopersmith of Emory University, Atlanta, coauthor of a related editorial, commented in an email to Reuters Health: “One important caveat in interpreting the results is that patients received only small to modest amounts of fluids in this study, and additional research is needed to determine whether rate or composition of fluids impacts survival or other important outcomes when larger amounts of fluids are given.”